1. Field of the Invention
The present invention relates to a jig saw.
2. Description of the Prior Art
EP 0544129 A1 discloses a jig saw having a chuck mechanism which provides convenience in mounting a saw blade on the jig saw and in removing the saw blade therefrom. The chuck mechanism has an operational cam formed on a tightening sleeve which is adapted to be rotated for mounting and removing the saw blade. A stopper edge is formed on a rotatable switching sleeve which is disposed outwardly of the tightening sleeve. The switching sleeve can be operable from the outside of a casing for rotating the tightening sleeve through engagement between the stopper edge and the operational cam of the tightening sleeve. With the chuck mechanism of this prior art, an operator can exchange the saw blade for a new one without directly touching the tightening sleeve, so that the operability of the chuck mechanism can be improved.
However, with the prior art jig saw, in order to attain such an improved operability, a separate switching sleeve must be mounted on the casing. Therefore, the jig saw is complicated in construction, and the manufacturing costs of the jig saw are increased.